HELIX VX-399 Installation, Operation & Maintanance Manual page 23

FIGURE 6-4 Side Wall Concentric Terminal
Combustion
Air
FIGURE 6-6 Concentric Terminal Connection
4" (102mm) Diameter PVC
intake/combustion air
Combustion Air
4"
6 - COMBUSTION AIR AND VENT PIPING
1"(2.54cm)
Maximum
1" (25.4mm)
Max.
Vent
Kit
(102mm)
4" (102mm) Diameter = 36" Length (0.9m)
** Note Overall length may be modified by cutting or extending
both combustion air and vent pipes. 12" (305mm) is minimum
allowable length and 60" (1.2m) is maximum allowable length for
this dimension.
SDR-26 PVC (D2241) only may be used for extending pipes.
Do not use Schedule 40 PVC or use couplings to extend pipes.
Dimension will change if intake/vent pipes are lengthened or
shortened.
FIGURE 6-5 Side Wall Concentric Terminal Multiple
Appliances
1" (25mm)
Max.
* See Note
Below
Combustion
Air
24" (610mm) minimum Horizontal distance between
end bells of each concentric terminal to prevent flue gas
recirculation.
Note: Securing strap must
be field installed to prevent
movement of termination
kit in side wall
**See
Note
23
Roof
Overhang
12" (305mm) Min.
36" (457mm) Min.
Maintain 12"
clearance above
Maintain 12"(30cm) US
Vent
highest anticipated
(18"(46cm) Canada)
snow level or grade
Clearance Above Highest
Anticipated Snow Level
Or Grade
1"(25.4mm)
Maximum
Vent
Combustion Air
P/N 240010943, Rev. C [09/07/2016]